This wonderfull Parisian based company called Printic, prints your iphone pictures (Facebook and Instagram as well) at the most easiest way. You need to install the app and then select the pictures you want to have printed and voila, they reach your mailbox in a pretty orange box if you choose the maximun amount of prints. They come only in a one size but if you want you can personalize them too. A minimum of 3 prints, and they cost 0,99$ each and free delivery worldwide.
I once spend 3 hours adding the images to an usb stick and then to have them printed in a store, waisting another 2 hours, it was worth it but now with Printic I can order pictures in a relaxed way, sitting on the sofa or from my cozy bed in the weekends, knowing it takes a few days for them to arrive to my doorstep.
Vive la Printic!